Help! 1st DIY rigg

Hi, this is my first time building my own rig and id like some help please
The current setup is:

CPU: intel i7 920
Video card: radon HD 5870
Sound card: X-FI Titanium
RAM: 8GB kit (2GBx4) unbuffered – non ECC - DDR3 PC3-12800
Motherboard: Maximus III Formula
Case: antec skeleton (1 top 250mm TriCool) (1 front 92mm HD cooling fan)
Power supply: Quattro 850w
HD: velociraptor 150gb – seagate barracuda 320gb

My three main concerns are:
Do I need extra cooling for the i7 (not planning to OverClock)
Is the power supply solid (i.e. will anything explode when I hook it up)
Is the skeleton really suitable for this rigg?

Im going for a high end gaming rigg under £1400 so if you see any more affordable alternatives id love to know.
thanks

first off hello,
the skeleton is not good for that build, no you dont really need extra cooling but it cant hurt, and instead of that psu and case, look at this combo deal.

http://www.newegg.com/Product/Comb [...] mbo.303755

it is wayyyy better and saves you some money too. also, get the 300 GB version of the raptor and then you can just forget about the 320 gb barracuda. or get an ssd, if you want to spend the extra money. also that motherboard is not compatible with your build (just caught that) consider getting:

ASUS P6T6 WS Revolution with NF200 3xPCIe true x16 LGA 1366 Intel X58 ATX Intel Motherboard
http://www.newegg.com/Product/Prod [...] 6813131358

or

ASUS P6X58D Premium LGA 1366 Intel X58 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
http://www.newegg.com/Product/Prod [...] 6813131614

those two are great, but you can go a bit lower end too.lastly, the ram isn't triple channel, so get
G.SKILL 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Triple Channel Kit Desktop Memory Model F3-10666CL7T-6GBPK
http://www.newegg.com/Product/Prod [...] 6820231230

now everything should work and work well.

I wouldn't do the skeleton unless you like cleaning dust and swapping stuff every other day.

The Antec 1200 w/ CP-850 PSU is an unbeatable combination...you don't need 850 watts but it costs the same as many good 650/750 watters and will let you Xfire down the road.

This MoBo has SATA 6 and USB3, quoite futureproofed

http://www.newegg.com/Product/Prod [...] 6813131614

Grab a Spinpoint F3 or Seagate 7200.12

If you can grab one of these, it's hot !

http://www.newegg.com/Product/Prod [...] 6814121346

as for memory, suggest cheapest CAS 7 DDR1600 in 3 x 2GB kit